(1) Field of the Invention
This invention relates to a speed change device for use in driving auxiliary machinery attached to internal combustion engines.
(2) Description of the Prior Art
In internal combustion engines such as automotive engines, for driving auxiliary machinery such as a generator, a water pump, a cooling fan, a cooler compressor and a power steering pump, there has been used a power transmission system comprising a pulley mounted on the crank shaft of an engine and a V-belt which transmission transmits the engine rotation directly at a fixed change gear ratio. Generally, these auxiliary machines are designed to exhibit required abilities at low engine speeds, so that at high engine speeds their abilities become excessive, thus causing loss of engine power and increase in fuel consumption.
For preventing the loss of engine power and for the saving in fuel consumption, it is effective to use, as the aforesaid power transmission system, a speed change device which decelerates upon increase in engine speed.